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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Intel & MS High Precision Event Timer Implementation. | |
3 | * | |
4 | * Copyright (C) 2003 Intel Corporation | |
5 | * Venki Pallipadi | |
6 | * (c) Copyright 2004 Hewlett-Packard Development Company, L.P. | |
7 | * Bob Picco <robert.picco@hp.com> | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify | |
10 | * it under the terms of the GNU General Public License version 2 as | |
11 | * published by the Free Software Foundation. | |
12 | */ | |
13 | ||
1da177e4 LT |
14 | #include <linux/interrupt.h> |
15 | #include <linux/module.h> | |
16 | #include <linux/kernel.h> | |
17 | #include <linux/types.h> | |
18 | #include <linux/miscdevice.h> | |
19 | #include <linux/major.h> | |
20 | #include <linux/ioport.h> | |
21 | #include <linux/fcntl.h> | |
22 | #include <linux/init.h> | |
23 | #include <linux/poll.h> | |
f23f6e08 | 24 | #include <linux/mm.h> |
1da177e4 LT |
25 | #include <linux/proc_fs.h> |
26 | #include <linux/spinlock.h> | |
27 | #include <linux/sysctl.h> | |
28 | #include <linux/wait.h> | |
29 | #include <linux/bcd.h> | |
30 | #include <linux/seq_file.h> | |
31 | #include <linux/bitops.h> | |
54066a57 | 32 | #include <linux/compat.h> |
0aa366f3 | 33 | #include <linux/clocksource.h> |
0ca01763 | 34 | #include <linux/uaccess.h> |
5a0e3ad6 | 35 | #include <linux/slab.h> |
0ca01763 | 36 | #include <linux/io.h> |
1da177e4 LT |
37 | |
38 | #include <asm/current.h> | |
1da177e4 LT |
39 | #include <asm/irq.h> |
40 | #include <asm/div64.h> | |
41 | ||
42 | #include <linux/acpi.h> | |
43 | #include <acpi/acpi_bus.h> | |
44 | #include <linux/hpet.h> | |
45 | ||
46 | /* | |
47 | * The High Precision Event Timer driver. | |
48 | * This driver is closely modelled after the rtc.c driver. | |
e45f2c07 | 49 | * http://www.intel.com/hardwaredesign/hpetspec_1.pdf |
1da177e4 LT |
50 | */ |
51 | #define HPET_USER_FREQ (64) | |
52 | #define HPET_DRIFT (500) | |
53 | ||
757c4724 RD |
54 | #define HPET_RANGE_SIZE 1024 /* from HPET spec */ |
55 | ||
64a76f66 DB |
56 | |
57 | /* WARNING -- don't get confused. These macros are never used | |
58 | * to write the (single) counter, and rarely to read it. | |
59 | * They're badly named; to fix, someday. | |
60 | */ | |
0aa366f3 TL |
61 | #if BITS_PER_LONG == 64 |
62 | #define write_counter(V, MC) writeq(V, MC) | |
63 | #define read_counter(MC) readq(MC) | |
64 | #else | |
65 | #define write_counter(V, MC) writel(V, MC) | |
66 | #define read_counter(MC) readl(MC) | |
67 | #endif | |
68 | ||
54066a57 | 69 | static DEFINE_MUTEX(hpet_mutex); /* replaces BKL */ |
642d30bb | 70 | static u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ; |
1da177e4 | 71 | |
3dffec45 ÇO |
72 | /* This clocksource driver currently only works on ia64 */ |
73 | #ifdef CONFIG_IA64 | |
0aa366f3 TL |
74 | static void __iomem *hpet_mctr; |
75 | ||
8e19608e | 76 | static cycle_t read_hpet(struct clocksource *cs) |
0aa366f3 TL |
77 | { |
78 | return (cycle_t)read_counter((void __iomem *)hpet_mctr); | |
79 | } | |
80 | ||
81 | static struct clocksource clocksource_hpet = { | |
0ca01763 JSR |
82 | .name = "hpet", |
83 | .rating = 250, | |
84 | .read = read_hpet, | |
85 | .mask = CLOCKSOURCE_MASK(64), | |
0ca01763 | 86 | .flags = CLOCK_SOURCE_IS_CONTINUOUS, |
0aa366f3 TL |
87 | }; |
88 | static struct clocksource *hpet_clocksource; | |
3dffec45 | 89 | #endif |
0aa366f3 | 90 | |
1da177e4 LT |
91 | /* A lock for concurrent access by app and isr hpet activity. */ |
92 | static DEFINE_SPINLOCK(hpet_lock); | |
1da177e4 LT |
93 | |
94 | #define HPET_DEV_NAME (7) | |
95 | ||
96 | struct hpet_dev { | |
97 | struct hpets *hd_hpets; | |
98 | struct hpet __iomem *hd_hpet; | |
99 | struct hpet_timer __iomem *hd_timer; | |
100 | unsigned long hd_ireqfreq; | |
101 | unsigned long hd_irqdata; | |
102 | wait_queue_head_t hd_waitqueue; | |
103 | struct fasync_struct *hd_async_queue; | |
1da177e4 LT |
104 | unsigned int hd_flags; |
105 | unsigned int hd_irq; | |
106 | unsigned int hd_hdwirq; | |
107 | char hd_name[HPET_DEV_NAME]; | |
108 | }; | |
109 | ||
110 | struct hpets { | |
111 | struct hpets *hp_next; | |
112 | struct hpet __iomem *hp_hpet; | |
113 | unsigned long hp_hpet_phys; | |
0aa366f3 | 114 | struct clocksource *hp_clocksource; |
ba3f213f | 115 | unsigned long long hp_tick_freq; |
1da177e4 LT |
116 | unsigned long hp_delta; |
117 | unsigned int hp_ntimer; | |
118 | unsigned int hp_which; | |
119 | struct hpet_dev hp_dev[1]; | |
120 | }; | |
121 | ||
122 | static struct hpets *hpets; | |
123 | ||
124 | #define HPET_OPEN 0x0001 | |
125 | #define HPET_IE 0x0002 /* interrupt enabled */ | |
126 | #define HPET_PERIODIC 0x0004 | |
0d290861 | 127 | #define HPET_SHARED_IRQ 0x0008 |
1da177e4 | 128 | |
1da177e4 LT |
129 | |
130 | #ifndef readq | |
887c27f3 | 131 | static inline unsigned long long readq(void __iomem *addr) |
1da177e4 LT |
132 | { |
133 | return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL); | |
134 | } | |
135 | #endif | |
136 | ||
137 | #ifndef writeq | |
887c27f3 | 138 | static inline void writeq(unsigned long long v, void __iomem *addr) |
1da177e4 LT |
139 | { |
140 | writel(v & 0xffffffff, addr); | |
141 | writel(v >> 32, addr + 4); | |
142 | } | |
143 | #endif | |
144 | ||
7d12e780 | 145 | static irqreturn_t hpet_interrupt(int irq, void *data) |
1da177e4 LT |
146 | { |
147 | struct hpet_dev *devp; | |
148 | unsigned long isr; | |
149 | ||
150 | devp = data; | |
0d290861 CL |
151 | isr = 1 << (devp - devp->hd_hpets->hp_dev); |
152 | ||
153 | if ((devp->hd_flags & HPET_SHARED_IRQ) && | |
154 | !(isr & readl(&devp->hd_hpet->hpet_isr))) | |
155 | return IRQ_NONE; | |
1da177e4 LT |
156 | |
157 | spin_lock(&hpet_lock); | |
158 | devp->hd_irqdata++; | |
159 | ||
160 | /* | |
161 | * For non-periodic timers, increment the accumulator. | |
162 | * This has the effect of treating non-periodic like periodic. | |
163 | */ | |
164 | if ((devp->hd_flags & (HPET_IE | HPET_PERIODIC)) == HPET_IE) { | |
273ef950 NC |
165 | unsigned long m, t, mc, base, k; |
166 | struct hpet __iomem *hpet = devp->hd_hpet; | |
167 | struct hpets *hpetp = devp->hd_hpets; | |
1da177e4 LT |
168 | |
169 | t = devp->hd_ireqfreq; | |
ae21cf92 | 170 | m = read_counter(&devp->hd_timer->hpet_compare); |
273ef950 NC |
171 | mc = read_counter(&hpet->hpet_mc); |
172 | /* The time for the next interrupt would logically be t + m, | |
173 | * however, if we are very unlucky and the interrupt is delayed | |
174 | * for longer than t then we will completely miss the next | |
175 | * interrupt if we set t + m and an application will hang. | |
176 | * Therefore we need to make a more complex computation assuming | |
177 | * that there exists a k for which the following is true: | |
178 | * k * t + base < mc + delta | |
179 | * (k + 1) * t + base > mc + delta | |
180 | * where t is the interval in hpet ticks for the given freq, | |
181 | * base is the theoretical start value 0 < base < t, | |
182 | * mc is the main counter value at the time of the interrupt, | |
183 | * delta is the time it takes to write the a value to the | |
184 | * comparator. | |
185 | * k may then be computed as (mc - base + delta) / t . | |
186 | */ | |
187 | base = mc % t; | |
188 | k = (mc - base + hpetp->hp_delta) / t; | |
189 | write_counter(t * (k + 1) + base, | |
190 | &devp->hd_timer->hpet_compare); | |
1da177e4 LT |
191 | } |
192 | ||
0d290861 CL |
193 | if (devp->hd_flags & HPET_SHARED_IRQ) |
194 | writel(isr, &devp->hd_hpet->hpet_isr); | |
1da177e4 LT |
195 | spin_unlock(&hpet_lock); |
196 | ||
1da177e4 LT |
197 | wake_up_interruptible(&devp->hd_waitqueue); |
198 | ||
199 | kill_fasync(&devp->hd_async_queue, SIGIO, POLL_IN); | |
200 | ||
201 | return IRQ_HANDLED; | |
202 | } | |
203 | ||
70ef6d59 KH |
204 | static void hpet_timer_set_irq(struct hpet_dev *devp) |
205 | { | |
206 | unsigned long v; | |
207 | int irq, gsi; | |
208 | struct hpet_timer __iomem *timer; | |
209 | ||
210 | spin_lock_irq(&hpet_lock); | |
211 | if (devp->hd_hdwirq) { | |
212 | spin_unlock_irq(&hpet_lock); | |
213 | return; | |
214 | } | |
215 | ||
216 | timer = devp->hd_timer; | |
217 | ||
218 | /* we prefer level triggered mode */ | |
219 | v = readl(&timer->hpet_config); | |
220 | if (!(v & Tn_INT_TYPE_CNF_MASK)) { | |
221 | v |= Tn_INT_TYPE_CNF_MASK; | |
222 | writel(v, &timer->hpet_config); | |
223 | } | |
224 | spin_unlock_irq(&hpet_lock); | |
225 | ||
226 | v = (readq(&timer->hpet_config) & Tn_INT_ROUTE_CAP_MASK) >> | |
227 | Tn_INT_ROUTE_CAP_SHIFT; | |
228 | ||
229 | /* | |
230 | * In PIC mode, skip IRQ0-4, IRQ6-9, IRQ12-15 which is always used by | |
231 | * legacy device. In IO APIC mode, we skip all the legacy IRQS. | |
232 | */ | |
233 | if (acpi_irq_model == ACPI_IRQ_MODEL_PIC) | |
234 | v &= ~0xf3df; | |
235 | else | |
236 | v &= ~0xffff; | |
237 | ||
e5d61511 | 238 | for_each_set_bit(irq, &v, HPET_MAX_IRQ) { |
1f45f562 | 239 | if (irq >= nr_irqs) { |
70ef6d59 KH |
240 | irq = HPET_MAX_IRQ; |
241 | break; | |
242 | } | |
243 | ||
a2f809b0 | 244 | gsi = acpi_register_gsi(NULL, irq, ACPI_LEVEL_SENSITIVE, |
70ef6d59 KH |
245 | ACPI_ACTIVE_LOW); |
246 | if (gsi > 0) | |
247 | break; | |
248 | ||
249 | /* FIXME: Setup interrupt source table */ | |
250 | } | |
251 | ||
252 | if (irq < HPET_MAX_IRQ) { | |
253 | spin_lock_irq(&hpet_lock); | |
254 | v = readl(&timer->hpet_config); | |
255 | v |= irq << Tn_INT_ROUTE_CNF_SHIFT; | |
256 | writel(v, &timer->hpet_config); | |
257 | devp->hd_hdwirq = gsi; | |
258 | spin_unlock_irq(&hpet_lock); | |
259 | } | |
260 | return; | |
261 | } | |
262 | ||
1da177e4 LT |
263 | static int hpet_open(struct inode *inode, struct file *file) |
264 | { | |
265 | struct hpet_dev *devp; | |
266 | struct hpets *hpetp; | |
267 | int i; | |
268 | ||
269 | if (file->f_mode & FMODE_WRITE) | |
270 | return -EINVAL; | |
271 | ||
54066a57 | 272 | mutex_lock(&hpet_mutex); |
1da177e4 LT |
273 | spin_lock_irq(&hpet_lock); |
274 | ||
275 | for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next) | |
276 | for (i = 0; i < hpetp->hp_ntimer; i++) | |
64a76f66 | 277 | if (hpetp->hp_dev[i].hd_flags & HPET_OPEN) |
1da177e4 LT |
278 | continue; |
279 | else { | |
280 | devp = &hpetp->hp_dev[i]; | |
281 | break; | |
282 | } | |
283 | ||
284 | if (!devp) { | |
285 | spin_unlock_irq(&hpet_lock); | |
54066a57 | 286 | mutex_unlock(&hpet_mutex); |
1da177e4 LT |
287 | return -EBUSY; |
288 | } | |
289 | ||
290 | file->private_data = devp; | |
291 | devp->hd_irqdata = 0; | |
292 | devp->hd_flags |= HPET_OPEN; | |
293 | spin_unlock_irq(&hpet_lock); | |
54066a57 | 294 | mutex_unlock(&hpet_mutex); |
1da177e4 | 295 | |
70ef6d59 KH |
296 | hpet_timer_set_irq(devp); |
297 | ||
1da177e4 LT |
298 | return 0; |
299 | } | |
300 | ||
301 | static ssize_t | |
302 | hpet_read(struct file *file, char __user *buf, size_t count, loff_t * ppos) | |
303 | { | |
304 | DECLARE_WAITQUEUE(wait, current); | |
305 | unsigned long data; | |
306 | ssize_t retval; | |
307 | struct hpet_dev *devp; | |
308 | ||
309 | devp = file->private_data; | |
310 | if (!devp->hd_ireqfreq) | |
311 | return -EIO; | |
312 | ||
313 | if (count < sizeof(unsigned long)) | |
314 | return -EINVAL; | |
315 | ||
316 | add_wait_queue(&devp->hd_waitqueue, &wait); | |
317 | ||
318 | for ( ; ; ) { | |
319 | set_current_state(TASK_INTERRUPTIBLE); | |
320 | ||
321 | spin_lock_irq(&hpet_lock); | |
322 | data = devp->hd_irqdata; | |
323 | devp->hd_irqdata = 0; | |
324 | spin_unlock_irq(&hpet_lock); | |
325 | ||
326 | if (data) | |
327 | break; | |
328 | else if (file->f_flags & O_NONBLOCK) { | |
329 | retval = -EAGAIN; | |
330 | goto out; | |
331 | } else if (signal_pending(current)) { | |
332 | retval = -ERESTARTSYS; | |
333 | goto out; | |
334 | } | |
335 | schedule(); | |
336 | } | |
337 | ||
338 | retval = put_user(data, (unsigned long __user *)buf); | |
339 | if (!retval) | |
340 | retval = sizeof(unsigned long); | |
341 | out: | |
342 | __set_current_state(TASK_RUNNING); | |
343 | remove_wait_queue(&devp->hd_waitqueue, &wait); | |
344 | ||
345 | return retval; | |
346 | } | |
347 | ||
348 | static unsigned int hpet_poll(struct file *file, poll_table * wait) | |
349 | { | |
350 | unsigned long v; | |
351 | struct hpet_dev *devp; | |
352 | ||
353 | devp = file->private_data; | |
354 | ||
355 | if (!devp->hd_ireqfreq) | |
356 | return 0; | |
357 | ||
358 | poll_wait(file, &devp->hd_waitqueue, wait); | |
359 | ||
360 | spin_lock_irq(&hpet_lock); | |
361 | v = devp->hd_irqdata; | |
362 | spin_unlock_irq(&hpet_lock); | |
363 | ||
364 | if (v != 0) | |
365 | return POLLIN | POLLRDNORM; | |
366 | ||
367 | return 0; | |
368 | } | |
369 | ||
3d035f58 PB |
370 | #ifdef CONFIG_HPET_MMAP |
371 | #ifdef CONFIG_HPET_MMAP_DEFAULT | |
372 | static int hpet_mmap_enabled = 1; | |
373 | #else | |
374 | static int hpet_mmap_enabled = 0; | |
375 | #endif | |
376 | ||
377 | static __init int hpet_mmap_enable(char *str) | |
378 | { | |
379 | get_option(&str, &hpet_mmap_enabled); | |
380 | pr_info("HPET mmap %s\n", hpet_mmap_enabled ? "enabled" : "disabled"); | |
381 | return 1; | |
382 | } | |
383 | __setup("hpet_mmap", hpet_mmap_enable); | |
384 | ||
1da177e4 LT |
385 | static int hpet_mmap(struct file *file, struct vm_area_struct *vma) |
386 | { | |
1da177e4 LT |
387 | struct hpet_dev *devp; |
388 | unsigned long addr; | |
389 | ||
3d035f58 PB |
390 | if (!hpet_mmap_enabled) |
391 | return -EACCES; | |
392 | ||
1da177e4 LT |
393 | devp = file->private_data; |
394 | addr = devp->hd_hpets->hp_hpet_phys; | |
395 | ||
396 | if (addr & (PAGE_SIZE - 1)) | |
397 | return -ENOSYS; | |
398 | ||
1da177e4 | 399 | vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); |
2323036d | 400 | return vm_iomap_memory(vma, addr, PAGE_SIZE); |
3d035f58 | 401 | } |
1da177e4 | 402 | #else |
3d035f58 PB |
403 | static int hpet_mmap(struct file *file, struct vm_area_struct *vma) |
404 | { | |
1da177e4 | 405 | return -ENOSYS; |
1da177e4 | 406 | } |
3d035f58 | 407 | #endif |
1da177e4 LT |
408 | |
409 | static int hpet_fasync(int fd, struct file *file, int on) | |
410 | { | |
411 | struct hpet_dev *devp; | |
412 | ||
413 | devp = file->private_data; | |
414 | ||
415 | if (fasync_helper(fd, file, on, &devp->hd_async_queue) >= 0) | |
416 | return 0; | |
417 | else | |
418 | return -EIO; | |
419 | } | |
420 | ||
421 | static int hpet_release(struct inode *inode, struct file *file) | |
422 | { | |
423 | struct hpet_dev *devp; | |
424 | struct hpet_timer __iomem *timer; | |
425 | int irq = 0; | |
426 | ||
427 | devp = file->private_data; | |
428 | timer = devp->hd_timer; | |
429 | ||
430 | spin_lock_irq(&hpet_lock); | |
431 | ||
432 | writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK), | |
433 | &timer->hpet_config); | |
434 | ||
435 | irq = devp->hd_irq; | |
436 | devp->hd_irq = 0; | |
437 | ||
438 | devp->hd_ireqfreq = 0; | |
439 | ||
440 | if (devp->hd_flags & HPET_PERIODIC | |
441 | && readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) { | |
442 | unsigned long v; | |
443 | ||
444 | v = readq(&timer->hpet_config); | |
445 | v ^= Tn_TYPE_CNF_MASK; | |
446 | writeq(v, &timer->hpet_config); | |
447 | } | |
448 | ||
449 | devp->hd_flags &= ~(HPET_OPEN | HPET_IE | HPET_PERIODIC); | |
450 | spin_unlock_irq(&hpet_lock); | |
451 | ||
452 | if (irq) | |
453 | free_irq(irq, devp); | |
454 | ||
1da177e4 LT |
455 | file->private_data = NULL; |
456 | return 0; | |
457 | } | |
458 | ||
1da177e4 LT |
459 | static int hpet_ioctl_ieon(struct hpet_dev *devp) |
460 | { | |
461 | struct hpet_timer __iomem *timer; | |
462 | struct hpet __iomem *hpet; | |
463 | struct hpets *hpetp; | |
464 | int irq; | |
465 | unsigned long g, v, t, m; | |
466 | unsigned long flags, isr; | |
467 | ||
468 | timer = devp->hd_timer; | |
469 | hpet = devp->hd_hpet; | |
470 | hpetp = devp->hd_hpets; | |
471 | ||
9090e6db CL |
472 | if (!devp->hd_ireqfreq) |
473 | return -EIO; | |
474 | ||
1da177e4 LT |
475 | spin_lock_irq(&hpet_lock); |
476 | ||
477 | if (devp->hd_flags & HPET_IE) { | |
478 | spin_unlock_irq(&hpet_lock); | |
479 | return -EBUSY; | |
480 | } | |
481 | ||
482 | devp->hd_flags |= HPET_IE; | |
0d290861 CL |
483 | |
484 | if (readl(&timer->hpet_config) & Tn_INT_TYPE_CNF_MASK) | |
485 | devp->hd_flags |= HPET_SHARED_IRQ; | |
1da177e4 LT |
486 | spin_unlock_irq(&hpet_lock); |
487 | ||
1da177e4 LT |
488 | irq = devp->hd_hdwirq; |
489 | ||
490 | if (irq) { | |
0d290861 | 491 | unsigned long irq_flags; |
1da177e4 | 492 | |
96e9694d CL |
493 | if (devp->hd_flags & HPET_SHARED_IRQ) { |
494 | /* | |
495 | * To prevent the interrupt handler from seeing an | |
496 | * unwanted interrupt status bit, program the timer | |
497 | * so that it will not fire in the near future ... | |
498 | */ | |
499 | writel(readl(&timer->hpet_config) & ~Tn_TYPE_CNF_MASK, | |
500 | &timer->hpet_config); | |
501 | write_counter(read_counter(&hpet->hpet_mc), | |
502 | &timer->hpet_compare); | |
503 | /* ... and clear any left-over status. */ | |
504 | isr = 1 << (devp - devp->hd_hpets->hp_dev); | |
505 | writel(isr, &hpet->hpet_isr); | |
506 | } | |
507 | ||
0d290861 | 508 | sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev)); |
158f0bb0 | 509 | irq_flags = devp->hd_flags & HPET_SHARED_IRQ ? IRQF_SHARED : 0; |
0d290861 CL |
510 | if (request_irq(irq, hpet_interrupt, irq_flags, |
511 | devp->hd_name, (void *)devp)) { | |
1da177e4 LT |
512 | printk(KERN_ERR "hpet: IRQ %d is not free\n", irq); |
513 | irq = 0; | |
514 | } | |
515 | } | |
516 | ||
517 | if (irq == 0) { | |
518 | spin_lock_irq(&hpet_lock); | |
519 | devp->hd_flags ^= HPET_IE; | |
520 | spin_unlock_irq(&hpet_lock); | |
521 | return -EIO; | |
522 | } | |
523 | ||
524 | devp->hd_irq = irq; | |
525 | t = devp->hd_ireqfreq; | |
526 | v = readq(&timer->hpet_config); | |
64a76f66 DB |
527 | |
528 | /* 64-bit comparators are not yet supported through the ioctls, | |
529 | * so force this into 32-bit mode if it supports both modes | |
530 | */ | |
531 | g = v | Tn_32MODE_CNF_MASK | Tn_INT_ENB_CNF_MASK; | |
1da177e4 LT |
532 | |
533 | if (devp->hd_flags & HPET_PERIODIC) { | |
1da177e4 | 534 | g |= Tn_TYPE_CNF_MASK; |
ae21cf92 | 535 | v |= Tn_TYPE_CNF_MASK | Tn_VAL_SET_CNF_MASK; |
1da177e4 LT |
536 | writeq(v, &timer->hpet_config); |
537 | local_irq_save(flags); | |
64a76f66 | 538 | |
ae21cf92 NC |
539 | /* |
540 | * NOTE: First we modify the hidden accumulator | |
64a76f66 DB |
541 | * register supported by periodic-capable comparators. |
542 | * We never want to modify the (single) counter; that | |
ae21cf92 NC |
543 | * would affect all the comparators. The value written |
544 | * is the counter value when the first interrupt is due. | |
64a76f66 | 545 | */ |
1da177e4 LT |
546 | m = read_counter(&hpet->hpet_mc); |
547 | write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare); | |
ae21cf92 NC |
548 | /* |
549 | * Then we modify the comparator, indicating the period | |
550 | * for subsequent interrupt. | |
551 | */ | |
552 | write_counter(t, &timer->hpet_compare); | |
1da177e4 LT |
553 | } else { |
554 | local_irq_save(flags); | |
555 | m = read_counter(&hpet->hpet_mc); | |
556 | write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare); | |
557 | } | |
558 | ||
0d290861 | 559 | if (devp->hd_flags & HPET_SHARED_IRQ) { |
3d5640d1 | 560 | isr = 1 << (devp - devp->hd_hpets->hp_dev); |
0d290861 CL |
561 | writel(isr, &hpet->hpet_isr); |
562 | } | |
1da177e4 LT |
563 | writeq(g, &timer->hpet_config); |
564 | local_irq_restore(flags); | |
565 | ||
566 | return 0; | |
567 | } | |
568 | ||
ba3f213f CL |
569 | /* converts Hz to number of timer ticks */ |
570 | static inline unsigned long hpet_time_div(struct hpets *hpets, | |
571 | unsigned long dis) | |
1da177e4 | 572 | { |
ba3f213f | 573 | unsigned long long m; |
1da177e4 | 574 | |
ba3f213f | 575 | m = hpets->hp_tick_freq + (dis >> 1); |
1da177e4 | 576 | do_div(m, dis); |
1da177e4 LT |
577 | return (unsigned long)m; |
578 | } | |
579 | ||
580 | static int | |
54066a57 AB |
581 | hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, |
582 | struct hpet_info *info) | |
1da177e4 LT |
583 | { |
584 | struct hpet_timer __iomem *timer; | |
585 | struct hpet __iomem *hpet; | |
586 | struct hpets *hpetp; | |
587 | int err; | |
588 | unsigned long v; | |
589 | ||
590 | switch (cmd) { | |
591 | case HPET_IE_OFF: | |
592 | case HPET_INFO: | |
593 | case HPET_EPI: | |
594 | case HPET_DPI: | |
595 | case HPET_IRQFREQ: | |
596 | timer = devp->hd_timer; | |
597 | hpet = devp->hd_hpet; | |
598 | hpetp = devp->hd_hpets; | |
599 | break; | |
600 | case HPET_IE_ON: | |
601 | return hpet_ioctl_ieon(devp); | |
602 | default: | |
603 | return -EINVAL; | |
604 | } | |
605 | ||
606 | err = 0; | |
607 | ||
608 | switch (cmd) { | |
609 | case HPET_IE_OFF: | |
610 | if ((devp->hd_flags & HPET_IE) == 0) | |
611 | break; | |
612 | v = readq(&timer->hpet_config); | |
613 | v &= ~Tn_INT_ENB_CNF_MASK; | |
614 | writeq(v, &timer->hpet_config); | |
615 | if (devp->hd_irq) { | |
616 | free_irq(devp->hd_irq, devp); | |
617 | devp->hd_irq = 0; | |
618 | } | |
619 | devp->hd_flags ^= HPET_IE; | |
620 | break; | |
621 | case HPET_INFO: | |
622 | { | |
dae512ed | 623 | memset(info, 0, sizeof(*info)); |
af95eade | 624 | if (devp->hd_ireqfreq) |
54066a57 | 625 | info->hi_ireqfreq = |
af95eade | 626 | hpet_time_div(hpetp, devp->hd_ireqfreq); |
54066a57 | 627 | info->hi_flags = |
1da177e4 | 628 | readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK; |
54066a57 AB |
629 | info->hi_hpet = hpetp->hp_which; |
630 | info->hi_timer = devp - hpetp->hp_dev; | |
1da177e4 LT |
631 | break; |
632 | } | |
633 | case HPET_EPI: | |
634 | v = readq(&timer->hpet_config); | |
635 | if ((v & Tn_PER_INT_CAP_MASK) == 0) { | |
636 | err = -ENXIO; | |
637 | break; | |
638 | } | |
639 | devp->hd_flags |= HPET_PERIODIC; | |
640 | break; | |
641 | case HPET_DPI: | |
642 | v = readq(&timer->hpet_config); | |
643 | if ((v & Tn_PER_INT_CAP_MASK) == 0) { | |
644 | err = -ENXIO; | |
645 | break; | |
646 | } | |
647 | if (devp->hd_flags & HPET_PERIODIC && | |
648 | readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) { | |
649 | v = readq(&timer->hpet_config); | |
650 | v ^= Tn_TYPE_CNF_MASK; | |
651 | writeq(v, &timer->hpet_config); | |
652 | } | |
653 | devp->hd_flags &= ~HPET_PERIODIC; | |
654 | break; | |
655 | case HPET_IRQFREQ: | |
54066a57 | 656 | if ((arg > hpet_max_freq) && |
1da177e4 LT |
657 | !capable(CAP_SYS_RESOURCE)) { |
658 | err = -EACCES; | |
659 | break; | |
660 | } | |
661 | ||
189e2dd1 | 662 | if (!arg) { |
1da177e4 LT |
663 | err = -EINVAL; |
664 | break; | |
665 | } | |
666 | ||
ba3f213f | 667 | devp->hd_ireqfreq = hpet_time_div(hpetp, arg); |
1da177e4 LT |
668 | } |
669 | ||
670 | return err; | |
671 | } | |
672 | ||
54066a57 AB |
673 | static long |
674 | hpet_ioctl(struct file *file, unsigned int cmd, unsigned long arg) | |
675 | { | |
676 | struct hpet_info info; | |
677 | int err; | |
678 | ||
679 | mutex_lock(&hpet_mutex); | |
680 | err = hpet_ioctl_common(file->private_data, cmd, arg, &info); | |
681 | mutex_unlock(&hpet_mutex); | |
682 | ||
683 | if ((cmd == HPET_INFO) && !err && | |
684 | (copy_to_user((void __user *)arg, &info, sizeof(info)))) | |
685 | err = -EFAULT; | |
686 | ||
687 | return err; | |
688 | } | |
689 | ||
690 | #ifdef CONFIG_COMPAT | |
691 | struct compat_hpet_info { | |
692 | compat_ulong_t hi_ireqfreq; /* Hz */ | |
693 | compat_ulong_t hi_flags; /* information */ | |
694 | unsigned short hi_hpet; | |
695 | unsigned short hi_timer; | |
696 | }; | |
697 | ||
698 | static long | |
699 | hpet_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) | |
700 | { | |
701 | struct hpet_info info; | |
702 | int err; | |
703 | ||
704 | mutex_lock(&hpet_mutex); | |
705 | err = hpet_ioctl_common(file->private_data, cmd, arg, &info); | |
706 | mutex_unlock(&hpet_mutex); | |
707 | ||
708 | if ((cmd == HPET_INFO) && !err) { | |
709 | struct compat_hpet_info __user *u = compat_ptr(arg); | |
710 | if (put_user(info.hi_ireqfreq, &u->hi_ireqfreq) || | |
711 | put_user(info.hi_flags, &u->hi_flags) || | |
712 | put_user(info.hi_hpet, &u->hi_hpet) || | |
713 | put_user(info.hi_timer, &u->hi_timer)) | |
714 | err = -EFAULT; | |
715 | } | |
716 | ||
717 | return err; | |
718 | } | |
719 | #endif | |
720 | ||
62322d25 | 721 | static const struct file_operations hpet_fops = { |
1da177e4 LT |
722 | .owner = THIS_MODULE, |
723 | .llseek = no_llseek, | |
724 | .read = hpet_read, | |
725 | .poll = hpet_poll, | |
55929332 | 726 | .unlocked_ioctl = hpet_ioctl, |
54066a57 AB |
727 | #ifdef CONFIG_COMPAT |
728 | .compat_ioctl = hpet_compat_ioctl, | |
729 | #endif | |
1da177e4 LT |
730 | .open = hpet_open, |
731 | .release = hpet_release, | |
732 | .fasync = hpet_fasync, | |
733 | .mmap = hpet_mmap, | |
734 | }; | |
735 | ||
3e6716e7 RD |
736 | static int hpet_is_known(struct hpet_data *hdp) |
737 | { | |
738 | struct hpets *hpetp; | |
739 | ||
740 | for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next) | |
741 | if (hpetp->hp_hpet_phys == hdp->hd_phys_address) | |
742 | return 1; | |
743 | ||
744 | return 0; | |
745 | } | |
746 | ||
a151427e | 747 | static struct ctl_table hpet_table[] = { |
1da177e4 | 748 | { |
1da177e4 LT |
749 | .procname = "max-user-freq", |
750 | .data = &hpet_max_freq, | |
751 | .maxlen = sizeof(int), | |
752 | .mode = 0644, | |
6d456111 | 753 | .proc_handler = proc_dointvec, |
1da177e4 | 754 | }, |
894d2491 | 755 | {} |
1da177e4 LT |
756 | }; |
757 | ||
a151427e | 758 | static struct ctl_table hpet_root[] = { |
1da177e4 | 759 | { |
1da177e4 LT |
760 | .procname = "hpet", |
761 | .maxlen = 0, | |
762 | .mode = 0555, | |
763 | .child = hpet_table, | |
764 | }, | |
894d2491 | 765 | {} |
1da177e4 LT |
766 | }; |
767 | ||
a151427e | 768 | static struct ctl_table dev_root[] = { |
1da177e4 | 769 | { |
1da177e4 LT |
770 | .procname = "dev", |
771 | .maxlen = 0, | |
772 | .mode = 0555, | |
773 | .child = hpet_root, | |
774 | }, | |
894d2491 | 775 | {} |
1da177e4 LT |
776 | }; |
777 | ||
778 | static struct ctl_table_header *sysctl_header; | |
779 | ||
1da177e4 LT |
780 | /* |
781 | * Adjustment for when arming the timer with | |
782 | * initial conditions. That is, main counter | |
783 | * ticks expired before interrupts are enabled. | |
784 | */ | |
785 | #define TICK_CALIBRATE (1000UL) | |
786 | ||
303d379c | 787 | static unsigned long __hpet_calibrate(struct hpets *hpetp) |
1da177e4 LT |
788 | { |
789 | struct hpet_timer __iomem *timer = NULL; | |
790 | unsigned long t, m, count, i, flags, start; | |
791 | struct hpet_dev *devp; | |
792 | int j; | |
793 | struct hpet __iomem *hpet; | |
794 | ||
795 | for (j = 0, devp = hpetp->hp_dev; j < hpetp->hp_ntimer; j++, devp++) | |
796 | if ((devp->hd_flags & HPET_OPEN) == 0) { | |
797 | timer = devp->hd_timer; | |
798 | break; | |
799 | } | |
800 | ||
801 | if (!timer) | |
802 | return 0; | |
803 | ||
3d5640d1 | 804 | hpet = hpetp->hp_hpet; |
1da177e4 LT |
805 | t = read_counter(&timer->hpet_compare); |
806 | ||
807 | i = 0; | |
ba3f213f | 808 | count = hpet_time_div(hpetp, TICK_CALIBRATE); |
1da177e4 LT |
809 | |
810 | local_irq_save(flags); | |
811 | ||
812 | start = read_counter(&hpet->hpet_mc); | |
813 | ||
814 | do { | |
815 | m = read_counter(&hpet->hpet_mc); | |
816 | write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare); | |
817 | } while (i++, (m - start) < count); | |
818 | ||
819 | local_irq_restore(flags); | |
820 | ||
821 | return (m - start) / i; | |
822 | } | |
823 | ||
303d379c YG |
824 | static unsigned long hpet_calibrate(struct hpets *hpetp) |
825 | { | |
2cf4e52e | 826 | unsigned long ret = ~0UL; |
303d379c YG |
827 | unsigned long tmp; |
828 | ||
829 | /* | |
830 | * Try to calibrate until return value becomes stable small value. | |
831 | * If SMI interruption occurs in calibration loop, the return value | |
832 | * will be big. This avoids its impact. | |
833 | */ | |
834 | for ( ; ; ) { | |
835 | tmp = __hpet_calibrate(hpetp); | |
836 | if (ret <= tmp) | |
837 | break; | |
838 | ret = tmp; | |
839 | } | |
840 | ||
841 | return ret; | |
842 | } | |
843 | ||
1da177e4 LT |
844 | int hpet_alloc(struct hpet_data *hdp) |
845 | { | |
5761d64b | 846 | u64 cap, mcfg; |
1da177e4 | 847 | struct hpet_dev *devp; |
5761d64b | 848 | u32 i, ntimer; |
1da177e4 LT |
849 | struct hpets *hpetp; |
850 | size_t siz; | |
851 | struct hpet __iomem *hpet; | |
0ca01763 | 852 | static struct hpets *last; |
5761d64b | 853 | unsigned long period; |
ba3f213f | 854 | unsigned long long temp; |
f92a789d | 855 | u32 remainder; |
1da177e4 LT |
856 | |
857 | /* | |
858 | * hpet_alloc can be called by platform dependent code. | |
3e6716e7 RD |
859 | * If platform dependent code has allocated the hpet that |
860 | * ACPI has also reported, then we catch it here. | |
1da177e4 | 861 | */ |
3e6716e7 RD |
862 | if (hpet_is_known(hdp)) { |
863 | printk(KERN_DEBUG "%s: duplicate HPET ignored\n", | |
bf9d8929 | 864 | __func__); |
3e6716e7 RD |
865 | return 0; |
866 | } | |
1da177e4 LT |
867 | |
868 | siz = sizeof(struct hpets) + ((hdp->hd_nirqs - 1) * | |
869 | sizeof(struct hpet_dev)); | |
870 | ||
3e6716e7 | 871 | hpetp = kzalloc(siz, GFP_KERNEL); |
1da177e4 LT |
872 | |
873 | if (!hpetp) | |
874 | return -ENOMEM; | |
875 | ||
1da177e4 LT |
876 | hpetp->hp_which = hpet_nhpet++; |
877 | hpetp->hp_hpet = hdp->hd_address; | |
878 | hpetp->hp_hpet_phys = hdp->hd_phys_address; | |
879 | ||
880 | hpetp->hp_ntimer = hdp->hd_nirqs; | |
e3f37a54 | 881 | |
5761d64b TG |
882 | for (i = 0; i < hdp->hd_nirqs; i++) |
883 | hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i]; | |
37a47db8 | 884 | |
5761d64b | 885 | hpet = hpetp->hp_hpet; |
e3f37a54 | 886 | |
1da177e4 LT |
887 | cap = readq(&hpet->hpet_cap); |
888 | ||
889 | ntimer = ((cap & HPET_NUM_TIM_CAP_MASK) >> HPET_NUM_TIM_CAP_SHIFT) + 1; | |
890 | ||
891 | if (hpetp->hp_ntimer != ntimer) { | |
892 | printk(KERN_WARNING "hpet: number irqs doesn't agree" | |
893 | " with number of timers\n"); | |
894 | kfree(hpetp); | |
895 | return -ENODEV; | |
896 | } | |
897 | ||
898 | if (last) | |
899 | last->hp_next = hpetp; | |
900 | else | |
901 | hpets = hpetp; | |
902 | ||
903 | last = hpetp; | |
904 | ||
ba3f213f CL |
905 | period = (cap & HPET_COUNTER_CLK_PERIOD_MASK) >> |
906 | HPET_COUNTER_CLK_PERIOD_SHIFT; /* fs, 10^-15 */ | |
907 | temp = 1000000000000000uLL; /* 10^15 femtoseconds per second */ | |
908 | temp += period >> 1; /* round */ | |
909 | do_div(temp, period); | |
910 | hpetp->hp_tick_freq = temp; /* ticks per second */ | |
1da177e4 | 911 | |
3034d11c AK |
912 | printk(KERN_INFO "hpet%d: at MMIO 0x%lx, IRQ%s", |
913 | hpetp->hp_which, hdp->hd_phys_address, | |
1da177e4 LT |
914 | hpetp->hp_ntimer > 1 ? "s" : ""); |
915 | for (i = 0; i < hpetp->hp_ntimer; i++) | |
5da527aa KS |
916 | printk(KERN_CONT "%s %d", i > 0 ? "," : "", hdp->hd_irq[i]); |
917 | printk(KERN_CONT "\n"); | |
1da177e4 | 918 | |
f92a789d DB |
919 | temp = hpetp->hp_tick_freq; |
920 | remainder = do_div(temp, 1000000); | |
64a76f66 DB |
921 | printk(KERN_INFO |
922 | "hpet%u: %u comparators, %d-bit %u.%06u MHz counter\n", | |
923 | hpetp->hp_which, hpetp->hp_ntimer, | |
924 | cap & HPET_COUNTER_SIZE_MASK ? 64 : 32, | |
f92a789d | 925 | (unsigned) temp, remainder); |
1da177e4 LT |
926 | |
927 | mcfg = readq(&hpet->hpet_config); | |
928 | if ((mcfg & HPET_ENABLE_CNF_MASK) == 0) { | |
929 | write_counter(0L, &hpet->hpet_mc); | |
930 | mcfg |= HPET_ENABLE_CNF_MASK; | |
931 | writeq(mcfg, &hpet->hpet_config); | |
932 | } | |
933 | ||
642d30bb | 934 | for (i = 0, devp = hpetp->hp_dev; i < hpetp->hp_ntimer; i++, devp++) { |
1da177e4 LT |
935 | struct hpet_timer __iomem *timer; |
936 | ||
937 | timer = &hpet->hpet_timers[devp - hpetp->hp_dev]; | |
1da177e4 LT |
938 | |
939 | devp->hd_hpets = hpetp; | |
940 | devp->hd_hpet = hpet; | |
941 | devp->hd_timer = timer; | |
942 | ||
943 | /* | |
944 | * If the timer was reserved by platform code, | |
945 | * then make timer unavailable for opens. | |
946 | */ | |
947 | if (hdp->hd_state & (1 << i)) { | |
948 | devp->hd_flags = HPET_OPEN; | |
949 | continue; | |
950 | } | |
951 | ||
952 | init_waitqueue_head(&devp->hd_waitqueue); | |
953 | } | |
954 | ||
955 | hpetp->hp_delta = hpet_calibrate(hpetp); | |
0aa366f3 | 956 | |
3b2b64fd LT |
957 | /* This clocksource driver currently only works on ia64 */ |
958 | #ifdef CONFIG_IA64 | |
0aa366f3 TL |
959 | if (!hpet_clocksource) { |
960 | hpet_mctr = (void __iomem *)&hpetp->hp_hpet->hpet_mc; | |
574c44fa | 961 | clocksource_hpet.archdata.fsys_mmio = hpet_mctr; |
d60c3041 | 962 | clocksource_register_hz(&clocksource_hpet, hpetp->hp_tick_freq); |
0aa366f3 TL |
963 | hpetp->hp_clocksource = &clocksource_hpet; |
964 | hpet_clocksource = &clocksource_hpet; | |
965 | } | |
3b2b64fd | 966 | #endif |
1da177e4 LT |
967 | |
968 | return 0; | |
969 | } | |
970 | ||
971 | static acpi_status hpet_resources(struct acpi_resource *res, void *data) | |
972 | { | |
973 | struct hpet_data *hdp; | |
974 | acpi_status status; | |
975 | struct acpi_resource_address64 addr; | |
1da177e4 LT |
976 | |
977 | hdp = data; | |
978 | ||
979 | status = acpi_resource_to_address64(res, &addr); | |
980 | ||
981 | if (ACPI_SUCCESS(status)) { | |
50eca3eb | 982 | hdp->hd_phys_address = addr.minimum; |
9224a867 | 983 | hdp->hd_address = ioremap(addr.minimum, addr.address_length); |
1da177e4 | 984 | |
3e6716e7 | 985 | if (hpet_is_known(hdp)) { |
3e6716e7 | 986 | iounmap(hdp->hd_address); |
78e1ca49 | 987 | return AE_ALREADY_EXISTS; |
3e6716e7 | 988 | } |
50eca3eb BM |
989 | } else if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) { |
990 | struct acpi_resource_fixed_memory32 *fixmem32; | |
757c4724 RD |
991 | |
992 | fixmem32 = &res->data.fixed_memory32; | |
757c4724 | 993 | |
50eca3eb BM |
994 | hdp->hd_phys_address = fixmem32->address; |
995 | hdp->hd_address = ioremap(fixmem32->address, | |
757c4724 RD |
996 | HPET_RANGE_SIZE); |
997 | ||
3e6716e7 | 998 | if (hpet_is_known(hdp)) { |
3e6716e7 | 999 | iounmap(hdp->hd_address); |
78e1ca49 | 1000 | return AE_ALREADY_EXISTS; |
3e6716e7 | 1001 | } |
50eca3eb BM |
1002 | } else if (res->type == ACPI_RESOURCE_TYPE_EXTENDED_IRQ) { |
1003 | struct acpi_resource_extended_irq *irqp; | |
be5efffb | 1004 | int i, irq; |
1da177e4 LT |
1005 | |
1006 | irqp = &res->data.extended_irq; | |
1007 | ||
be5efffb | 1008 | for (i = 0; i < irqp->interrupt_count; i++) { |
2cf4e52e CG |
1009 | if (hdp->hd_nirqs >= HPET_MAX_TIMERS) |
1010 | break; | |
1011 | ||
a2f809b0 | 1012 | irq = acpi_register_gsi(NULL, irqp->interrupts[i], |
be5efffb BH |
1013 | irqp->triggering, irqp->polarity); |
1014 | if (irq < 0) | |
1015 | return AE_ERROR; | |
1016 | ||
1017 | hdp->hd_irq[hdp->hd_nirqs] = irq; | |
1018 | hdp->hd_nirqs++; | |
1da177e4 LT |
1019 | } |
1020 | } | |
1021 | ||
1022 | return AE_OK; | |
1023 | } | |
1024 | ||
1025 | static int hpet_acpi_add(struct acpi_device *device) | |
1026 | { | |
1027 | acpi_status result; | |
1028 | struct hpet_data data; | |
1029 | ||
1030 | memset(&data, 0, sizeof(data)); | |
1031 | ||
1032 | result = | |
1033 | acpi_walk_resources(device->handle, METHOD_NAME__CRS, | |
1034 | hpet_resources, &data); | |
1035 | ||
1036 | if (ACPI_FAILURE(result)) | |
1037 | return -ENODEV; | |
1038 | ||
1039 | if (!data.hd_address || !data.hd_nirqs) { | |
a56d5318 JS |
1040 | if (data.hd_address) |
1041 | iounmap(data.hd_address); | |
bf9d8929 | 1042 | printk("%s: no address or irqs in _CRS\n", __func__); |
1da177e4 LT |
1043 | return -ENODEV; |
1044 | } | |
1045 | ||
1046 | return hpet_alloc(&data); | |
1047 | } | |
1048 | ||
51fac838 | 1049 | static int hpet_acpi_remove(struct acpi_device *device) |
1da177e4 | 1050 | { |
0aa366f3 | 1051 | /* XXX need to unregister clocksource, dealloc mem, etc */ |
1da177e4 LT |
1052 | return -EINVAL; |
1053 | } | |
1054 | ||
1ba90e3a TR |
1055 | static const struct acpi_device_id hpet_device_ids[] = { |
1056 | {"PNP0103", 0}, | |
1057 | {"", 0}, | |
1058 | }; | |
1059 | MODULE_DEVICE_TABLE(acpi, hpet_device_ids); | |
1060 | ||
1da177e4 LT |
1061 | static struct acpi_driver hpet_acpi_driver = { |
1062 | .name = "hpet", | |
1ba90e3a | 1063 | .ids = hpet_device_ids, |
1da177e4 LT |
1064 | .ops = { |
1065 | .add = hpet_acpi_add, | |
1066 | .remove = hpet_acpi_remove, | |
1067 | }, | |
1068 | }; | |
1069 | ||
1070 | static struct miscdevice hpet_misc = { HPET_MINOR, "hpet", &hpet_fops }; | |
1071 | ||
1072 | static int __init hpet_init(void) | |
1073 | { | |
1074 | int result; | |
1075 | ||
1076 | result = misc_register(&hpet_misc); | |
1077 | if (result < 0) | |
1078 | return -ENODEV; | |
1079 | ||
0b4d4147 | 1080 | sysctl_header = register_sysctl_table(dev_root); |
1da177e4 LT |
1081 | |
1082 | result = acpi_bus_register_driver(&hpet_acpi_driver); | |
1083 | if (result < 0) { | |
1084 | if (sysctl_header) | |
1085 | unregister_sysctl_table(sysctl_header); | |
1086 | misc_deregister(&hpet_misc); | |
1087 | return result; | |
1088 | } | |
1089 | ||
1090 | return 0; | |
1091 | } | |
1092 | ||
1093 | static void __exit hpet_exit(void) | |
1094 | { | |
1095 | acpi_bus_unregister_driver(&hpet_acpi_driver); | |
1096 | ||
1097 | if (sysctl_header) | |
1098 | unregister_sysctl_table(sysctl_header); | |
1099 | misc_deregister(&hpet_misc); | |
1100 | ||
1101 | return; | |
1102 | } | |
1103 | ||
1104 | module_init(hpet_init); | |
1105 | module_exit(hpet_exit); | |
1106 | MODULE_AUTHOR("Bob Picco <Robert.Picco@hp.com>"); | |
1107 | MODULE_LICENSE("GPL"); |